The present invention relates to apparatus for cleaning cooling systems such as radiators and engine blocks, and more particularly relates to a simplified self-priming pump mechanism.
In my previous patent, U.S. Pat. No. 4,054,150, I disclosed an apparatus for cleaning a cooling system which utilized a back and forth agitation of cleaning fluid through the system being cleaned and which used negative pressure to cause deposits and the like to be removed from the cooling system. The apparatus disclosed in this patent used a pair of parallel cylinders having pistons mounted for reciprocation therein with each piston being provided with rings to provide a fluid-tight seal with the inner surface of the cylinder. A system of valves provided for major and minor flow within the cooling system responsive to the negative and positive pressure set up by the reciprocation of the piston. The apparatus performed its cleaning function quite satisfactorily; however, the fluid-tight fit of the pistons within the cylinders requires that the piston be lubricated. Unfortunately the lubricant contaminates the cleaning fluid and appreciably shortens the useful life thereof, thus necessitating frequent and costly replacement of the fluid. It is believed that the same problem would occur in any device which produced a negative and positive pressure to urge fluid through a system through the action of a close fitting piston such as may be seen in U.S. Pat. No. 2,380,694 issued to C. C. Melton.